SPID#: 46 The goal of this project is to establish a database for comparative neuroanatomy of primates using high resolution magnetic resonance imaging (MRI). The following species will be studied New World (Saimiri sciureus, Cebus apella), Old World (Macaca mulatta), Lesser Apes (Hylobates lar), and Great Apes (Pan paniscus, Pan troglodytes, Pongo pygmaeus, Gorilla gorilla). Three males and three females of each species will be compared. In the first year, at least one of each species (except G. gorilla) have been studied with a high resolution echoplanar scanning protocol that permits 3-dimensional reconstruction and segmentation analysis for measuring volumes. Comparisons across species are just beginning.